Late recurrence of ductal carcinoma in situ at the cutaneous end of surgical drainage following total mastectomy.

A 40-year-old woman underwent upper outer quadrantectomy breast biopsy which revealed extensive intraductal carcinoma, predominantly comedocarcinoma type, with high nuclear grade. Involved ducts were transected at the edge of the biopsy. Total mastectomy with low axillary lymph node dissection was performed 2 weeks later, showing residual intraductal carcinoma in the upper inner quadrant and no evidence of metastasis. Eight years later, the patient developed two separate foci of recurrent, invasive ductal carcinoma at the exit sites for mastectomy drainage in the subcutaneous skin of the upper abdomen. The mastectomy scar was clinically free of tumor. The biological basis for this unusual sequela of treated intraductal carcinoma is discussed together with its importance for management of early breast cancer.